US President Donald Trump has said he will send about 1,500 additional troops to the Middle East amid heightened tensions with rival Iran.

Axar.az reports citing AlJazeera.

Speaking to reporters on the White House lawn shortly before departing for a trip to Japan on Friday, Trump said the purpose of this deployment is "mostly protective", and is meant to increase the security of forces already in the region.

"We want to have protection in the Middle East. We're going to be sending a relatively small number of troops," Trump said.

"Right now, I don't think Iran wants to fight. And I certainly don't think they want to fight with us," he added.

The Trump administration had notified Congress earlier on Friday about the troop plans.

According to a copy of the notification obtained by the Associated Press news agency, the forces would number "roughly" 1,500 and would deploy in the coming weeks, "with their primary responsibilities and activities being defensive in nature".

At a Pentagon news briefing on Friday, officials said the US plans to send 900 more forces, including engineers and a fighter aircraft squadron, to the Middle East to bolster US defence and extend the deployment of some 600 personnel manning Patriot missiles.

Iranian Foreign Minister Javad Zarif reiterated his country's rejection of the US's increase in military deployments to the region while on a visit to Pakistan.

Iran "will see the end of Trump, but he will never see the end of Iran," Zarif was quoted by state news agency Fars as saying during his trip to the Pakistani capital Islamabad on Friday, before the US announced the troop increase.

Zarif held talks with Pakistani Prime Minister Imran Khan, Foreign Minister Shah Mehmood Qureshi and powerful army chief General Qamar Javed Bajwa.

"War is not in anyone's interest and all sides need to make efforts to keep conflict away from the region," General Bajwa said, according to a Pakistani military statement.

Earlier this month, the US sent a carrier attack group and bomber taskforce to the Middle East, citing a "credible threat" from Tehran.

The news came after acting US Secretary of Defense Patrick Shanahan denied earlier reports that the Trump administration was planning to send as many as 10,000 troops to the region.

Shanahan, however, said that sending additional troops was an option they were considering.